Yield and soil responses to adding wheat to a corn‐soybean rotation

Abstract. The net loss of soil organic carbon (SOC) from terrestrial ecosystems is a likely consequence of global warming and may affect key soil functions. The strongest changes in temperature are expected to occur at high northern latitudes, with forest and tundra as prevailing land cover types. However, specific soil responses to warming in different ecosystems are currently understudied. In this study, we used a natural geothermal soil warming gradient (0–17.5 ∘C warming intensity) in an Icelandic spruce forest on Andosol to assess changes in the SOC content between 0 and 10 cm (topsoil) and between 20 and 30 cm (subsoil) after 10 years of soil warming. Five different SOC fractions were isolated, and their redistribution and the amount of stable aggregates were assessed to link SOC to changes in the soil structure. The results were compared to an adjacent, previously investigated warmed grassland. Soil warming depleted the SOC content in the forest soil by −2.7 g kg−1 ∘C−1 (−3.6 % ∘C−1) in the topsoil and −1.6 g kg−1 ∘C−1 (−4.5 % ∘C−1) in the subsoil. The distribution of SOC in different fractions was significantly altered, with particulate organic matter and SOC in sand and stable aggregates being relatively depleted and SOC attached to silt and clay being relatively enriched in warmed soils. The major reason for this shift was aggregate breakdown: the topsoil aggregate mass proportion was reduced from 60.7±2.2 % in the unwarmed reference to 28.9±4.6 % in the most warmed soil. Across both depths, the loss of one unit of SOC caused a depletion of 4.5 units of aggregated soil, which strongly affected the bulk density (an R2 value of 0.91 and p<0.001 when correlated with SOC, and an R2 value of 0.51 and p<0.001 when correlated with soil mass in stable aggregates). The proportion of water-extractable carbon increased with decreasing aggregation, which might indicate an indirect protective effect of aggregates larger than 63 µm on SOC. Topsoil changes in the total SOC content and fraction distribution were more pronounced in the forest than in the adjacent warmed grassland soils, due to higher and more labile initial SOC. However, no ecosystem effect was observed on the warming response of the subsoil SOC content and fraction distribution. Thus, whole profile differences across ecosystems might be small. Changes in the soil structure upon warming should be studied more deeply and taken into consideration when interpreting or modelling biotic responses to warming.

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Soil Responses to Monotonic and Cyclic Lateral Displacement of a Buried Pipe

Journal of Pipeline Systems Engineering and Practice ◽

10.1061/(asce)ps.1949-1204.0000381 ◽

2019 ◽

Vol 10 (3) ◽

pp. 04019012 ◽

Cited By ~ 1

Author(s):

N. H. Minh ◽

D. Zhang

Keyword(s):

Lateral Displacement ◽

Buried Pipe ◽

Soil Responses

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Five native tree species and manioc under slash-and-mulch agroforestry in the eastern Amazon of Brazil: plant growth and soil responses

Agroforestry Systems ◽

10.1007/s10457-010-9356-1 ◽

2010 ◽

Vol 81 (1) ◽

pp. 1-14 ◽

Cited By ~ 18

Author(s):

Aaron H. Joslin ◽

Daniel Markewitz ◽

Lawrence A. Morris ◽

Francisco DeAssis Oliveira ◽

Ricardo O. Figueiredo ◽

...

Keyword(s):

Plant Growth ◽

Tree Species ◽

Native Tree ◽

Native Tree Species ◽

Soil Responses

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Soil and cotton responses to tillage and ameliorant treatments in a brown clay soil. 1. Soil responses and water use

Australian Journal of Experimental Agriculture ◽

10.1071/ea9700313 ◽

1970 ◽

Vol 10 (44) ◽

pp. 313 ◽

Cited By ~ 11

Author(s):

J Loveday ◽

JE Saunt ◽

PM Fleming ◽

WA Muirhead

Keyword(s):

Organic Matter ◽

Water Use ◽

Clay Soil ◽

Aggregate Stability ◽

Surface Layers ◽

Peak Period ◽

Relative Water ◽

Rate Of Decline ◽

The Hill ◽

Soil Responses

Furrow-irrigated cotton was grown for two seasons on a previously uncultivated dense clay soil to which the following treatments had been applied :--normal ploughing (18 cm), precision ripping (30 cm), deep ploughing (40 cm), deep ripping (60 cm), and deep ploughing and deep ripping combined, with and without applications of gypsum at 10 tons an acre or organic matter at 2 1/2 tons an acre. The deep tillage significantly increased the porosity of the subsoil, but this extra porosity had largely been lost by the end of the second season. Neither the gypsum nor the organic matter addition had a significant effect upon its rate of decline. Despite the effect on porosity the deep tillages had only small and mostly non-significant effects upon water increment at irrigation. The gypsum treatment, but not the organic matter, increased water entry to the subsoil at irrigation, and this W-as apparently a result of improved hydraulic conductivity and aggregate stability, particularly in the surface layers. Considerable leaching of chloride occurred from the 30-60 cm subsoil zone in both gypsum treated and deep-tilled plots, but not in organic matter plots, and an accumulation of chloride occurred in the 0-10 cm layer (the hill) in gypsum treated plots. The increased water intake to the subsoil resulting from gypsum treatment was matched by increased water use in the following period, and hence a reduction in relative water deficit of Leaves during the peak period of water demand. Neither the organic matter nor the deep tillages had appreciable influence on water uptake. Water use during periods of peak demand was about 6 mm a day for gypsum treated plots, and this was probably lower than mould have been obtained with water freely available at all times. On the other treatments it can he inferred that water use was even further reduced by lack of available water.

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